This invention is directed to both a method and an apparatus for the detection of chemically bound sulfur. Sulfur which is chemically bound may occur in either organic or inorganic compounds, which are equally susceptible to analysis. Typical compounds include sulfates, sulfides, sulfoxides and sulfites. The output of the apparatus is achieved through an observation of chemiluminescent conversion.
Various procedures for testing for sulfur compounds have been known heretofore. One example is described in U.S. Pat. No. 3,749,929, of Wooten. That disclosure sets forth a chemiluminescent method of detecting three various compounds through a chemiluminescent procedure with atomic oxygen. That disclosure leaves open the problem of sorting out the three compounds. This lack of discrimination is believed to be fatal to this approach.
The patent of Haas, U.S. Pat. No. 3,877,819, sets forth a hydrogen burner capable of detecting phosphorous or sulfur bearing vapors. It is said that chemiluminescence is used, but this appears inconsistent with the description found in that disclosure referencing a flame. More aptly, this appears to be a flame operated analytical process, as opposed to a flameless chemiluminescent reaction.
U.S. Pat. No. 4,097,239 of Patterson discloses a multiflame approach. Mention is made of a hydrogen rich atmosphere, but, even assuming that this is the case, this disclosure is directed to a flame photometric detection apparatus.
Several techniques exist for detection of sulfur dioxide, and one such disclosure is Neti, U.S. Pat. No. 4,077,774. This process utilizes a reactor to oxidize hydrocarbons and thereafter irradiates the gas output with ultraviolet light to measure the level of fluorescence as a result of the irradiation. Fluorescence measurement is thought to be a more gross phenomena in comparison with chemiluminescence and would appear not to have the dynamic range for trace quantities of the sort which can be detected by this disclosed method. Of lesser significance of the approaches set forth are U.S. Pat. Nos. 3,984,688, 3,973,917, 3,700,896 and 3,838,969.
Without being specific, the procedures disclosed in the references do not appear to have the dynamic range. While specific data indicating the lower limits of their sensitivity is not available, the sensitivity of the presently disclosed procedure is quite surprising, and a wide dynamic range appears available from this disclosed procedure.